1. Technical Field
The present invention relates generally to a method and a system for cleaning an interior reservoir of an implantable medical device, and more particularly, to a method and system for ultrasonic cleaning of a fluid reservoir of a vascular access device.
2. Background Information
Implantable medical devices are widely used in the medical field to enable recurrent access to internal body portions of a patient. One common example of such an implantable medical device is a vascular access device (VAD). A VAD typically includes an implantable body containing a fluid reservoir, or chamber, and a self-sealing septum that provides controlled access to the reservoir.
A VAD is implanted in a pocket formed in the anatomy of the patient. A catheter extends from a connector tube portion of the device for providing fluid communication with the vascular system (i.e., an artery or vein) of the patient. Typically, a non-coring needle is utilized to puncture the skin, and provide access to the fluid reservoir of the VAD through the septum. The reservoir fluidly communicates with the catheter, and thereby, with the artery or vein.
An implanted vascular access device is particularly useful when prolonged, repeated, and/or targeted injection of medications is required, thereby sparing a patient the constant search for a suitable vessel to achieve vascular access. Moreover, the use of the VAD obviates the need for a dressing to cover the access site, once the incision from implantation of the device heals. One common example of the use of a VAD is the infusion of therapeutic agents during chemotherapy. In such use, infusion of the therapeutic agent(s) may be optimized by controlling the amount, timing, and location in the body of drug dosing. In addition to the use of VADs for infusion as described, such devices are also useful for supplying blood products and nutrients into the vascular system, as well as for blood sampling.
Since recurrent access to the VAD is generally desired, the device is typically implanted in a subcutaneous pocket at a location that is readily accessible to a needle. Once implanted, the catheter extends from the connector tube of the vascular access device to a remote target site for providing repeatable access to the patient's vascular system. The device will generally be placed at a location in which it can be supported by the underlying bony structure, and at a location which is convenient and comfortable to the patient.
A complication that may be encountered with the use of a VAD or like implantable device is the accumulation of foreign materials, such as thrombus and sludge, in the interior reservoir of the device. When present, such foreign materials can occlude the reservoir, thereby interfering with the smooth flow of fluids into and out of the device. When such materials build-up to an excessive level, fluid flow can be prevented altogether, thereby rendering the device useless. When the flow of fluid is interrupted to the extent that satisfactory flow is no longer possible, it is generally necessary to surgically remove an occluded VAD, and replace it with a new unit. This action results in added expense, and in increased trauma to the patient.
It would be desirable to provide a method and a system for cleaning an interior reservoir of an implantable medical device, such as a vascular access device, while the device remains implanted in the patient.